Exam 2 - Shoulder Flashcards
What bones are included in the shoulder complex?
Clavicle, Scapula, Sternum, Humerus
What joints are included in the shoulder?
Sternoclavicular, Acromioclavicular, Scapulo-thoracic, Glenohumeral
What is the shoulder complex for?
Mobility and motion
What is the purpose of the shoulder complex?
Keep the Glenoid in the Glenoid fossa
What are the three parts of the sternum?
Manubrium, Body, Xiphoid process
What ribs are connected to the sternum?
1, 2, 3-7
Where is the clavicle convex?
Medially
Where is the clavicle concave?
Laterally
What is the orientation of the clavicle?
20 degrees behind the true frontal plane
How is the glenoid fossa oriented?
Face upward, 4 degrees up and 35 degrees anterior from frontal plane
Where is the scapular plane located, in terms of the frontal plane?
35 degrees anterior to the frontal plane
How is the glenoid oriented?
Oriented 35 degrees anterior, not in the pure frontal plane
What is the angle of inclincation?
An angle between the head of the humerus and the shaft of the humerus
What is the normal angle of inclincation?
135 degrees
How is the head of the humerus oriented?
30 degrees posteriorly
In the glenohumeral joint, what is the convex surface?
Head of the humerus
In the glenohumeral joint, what surface is concave?
Glenoid fossa
What is the anterior stabilizer of the sternoclavicular joint?
Sternocleidomastoid
What are the posterior stabilizers of the sternoclavicular joint?
Sternothyroid and sternohyoid
What is the inferior stabilizer of the sternoclavicular joint?
Subclavius
What ligaments stabilize the sternoclavicular joint?
Anterior Sternoclavicular Ligament, Posterior Sternoclavicular Ligament, Interclavicular Ligament and Articular Disc
What does the interclavicular ligament connect?
Both clavicles
What does the costoclavicular ligament stabilize?
Stabilizes the SC joint during all motions except clavicular depression
What are the five motions allowed at the sternoclavicular joint?
Protraction, Retraction, Elevation, Depression, Posterior Rotation
What is the primary purpose of the sternoclavicular joint?
To place the scapula in an optimal position to accept the head of the humerus
What type of joint is the clavicle and sternum?
Saddle joint
Where is the clavicle concave?
Anterior and Posterior
Where is the clavicle convex?
Superior/Inferior
Where is the sternal portion of the sternoclavicular joint convex?
Anterior/Posterior
Where is the sternal portion of the sternoclavicular joint concave?
Superior/Inferior
Which surface moves in the sternoclavicular joint?
Convex clavicle
Where does the sternoclavicular joint roll and slide in elevation and depression?
Opposite directions
What surface moves during sternoclavicular protraction and retraction?
Concave clavicle
Which direction does the sternoclavicular joint roll and slide during protraction/retraction?
Roll and slide in the same direction
Which motion in the sternoclavicular joint cannot be done independently?
Axial rotation
What happens to the sternoclavicular joint when the arm is raised?
The superior aspect of the clavicle rotates posteriorly about 20-35 degrees
What ligaments stabilize the acromioclavicular joint?
Capsule, Superior AC Joint Ligament, Inferior AC Joint ligament, Coracoclavicular ligament, articular disc
What are the two parts of the coracoclavicular ligament?
Trapezoid and Conoid
Why is the coracoclavicular ligament so important?
This ligament suspends UE
What are the osteokinematics and arthrokinematics for the acromioclavicular joint?
NONE. Plane joint
What motions are combined with scapulo-thoracic elevation?
Elevation at the Sternoclavicular joint and downward rotation at the Acromioclavicular ligament
What axis and plane do all motions in scapulo-thoracic elevation and depression act in?
A/P axis in the frontal plane
What two motions are combined with Scapulo-thoracic protraction and retraction?
Protraction at sternoclavicular joint and slight internal rotation at the acromioclavicular joint
What plane and axis does protraction and retraction at the scapulothoracic joint act in?
Horizontal plane, S/I axis
What two movements are combined in upward and downward rotation of the scapulothoracic joint?
elevation of the sternoclavicular joint and upward rotation of the acromioclavicular joint
What plane and axis do the motions involved in scapulothoracic upward and downward rotation occur in?
A/P axis in the frontal plane
What structures reinforce/deepen the glenohumeral joint?
Joint capsule, Capsular Ligaments, Coracohumeral Ligament, Long head of Biceps Brachii, Glenoid Labrum, Rotator Cuff Muscles, Scapulo-thoracic posture, negative intrascapular pressure
Which surface is convex in the glenohumeral joint?
Convex humerus
Which surface is concave in the glenohumeral joint?
Concave glenoid
What are the four capsular ligaments in the glenohumeral joint?
Superior Glenohumeral Ligament, Middle Glenohumeral Ligament, Inferior Gleonumeral Ligament, Coracohumeral Ligament
When is the superior glenohumeral ligament taut?
End range Adduction
What does the superior glenohumeral ligament prevent?
Inferior and anterior humeral head translation
What does the middle glenohumeral joint limit?
End range External rotation
What are the three sections of the inferior glenohumeral ligament?
Anterior, Posterior, Axillary Pouch
Which end of the inferior glenohumeral ligament is the strongest and thickest?
Anterior End
What does the anterior end of the inferior glenohumeral ligament resist?
Anterior humeral head translation in abducted and neutral position
When is the inferior glenohumeral ligament taut?
90 degrees of abduction
What is the purpose of the axillary pouch?
Support humeral head
What does the axillary pouch resist?
Inferior and anterior posterior translation of the humeral head
What is the purpose of the coracohumeral ligament?
Strengthens the capsule
What does the coracohumeral ligament blend with?
Superior capsule and supraspinatus tendon
When is the coracohumeral ligament taut?
Adduction
What does the coracohumeral ligament restrain?
Inferior translation and humeral head external rotation
What does the rotator cuff muscles do, in terms of the glenoid?
Reinforces and deepens the glenohumeral joint
What is the acronym for the rotator cuff muscles?
SITS
What type of stabilizer is the rotator cuff?
Dynamic stabilizer
What does the tendons of the rotator cuff muscles blend into?
The joint capsule
What does contraction of the rotator cuff muscles do to the humeral head?
Stabilizes and centralizes the humeral head in the fossa
What does the long head of the biceps brachii do to the GH joint?
Reinforces and deepens the joint
Where does the long head of the biceps brachii cross?
Superior to the humeral head
What does the long head of the biceps brachii restrict?
Anterior humeral head translation and superior humeral head migration
What does the glenoid labrum do to the glenohumeral joint?
Reinforces and deepens
What lines the glenoid labrum?
Fibrocartilage ring
What is the purpose of the glenoid labrum?
Increases contact area of the fossa with the humeral head and helps stabilize the GH joint
What movements are allowed at the glenohumeral joint?
Flexion/extension, abduction/adduction, internal/external rotation, horizontal abduction/adduction, scaption
What part of the glenohumeral joint is convex?
Humerus
What part of the glenohumeral joint is concave?
Glenoid
What arthrokinematic movement happens in flexion/extetnsion?
Spin
What two joints are included in glenohumeral flexion?
120 degrees of GH flexion, 60 degrees of ST flexion
What is the ROM norms for passive GH extension?
65 degrees
What is the ROM norms for active GH extension?
80 degrees
Which direction does the humerus roll and slide in the GH joint?
Rolls and slides in opposite directions
How many degrees of abduction does the glenohumeral joint have?
120 degrees
What is scapulo-humeral rhythm?
The combination of GH abduction and ST upward rotation to achieve 180 degrees of shoulder abduction
Where is the subacromial bursa located?
In subacromial space
What is the function of the subacromial bursa?
To protect the supraspinatus muscle and tendon from the AC joint
What is the other bursa in the shoulder that is an extension of the subacromial bursa?
Subdeltoid Bursa
What is the function of the subdeltoid bursa?
Limits friction between deltoid, supraspinatus and humeral head
What three muscles of the rotator cuff are external rotators?
Supraspinatus, Infraspinatus, Teres Minor
What muscle of the rotator cuff is an internal rotator?
Subscapularis
What does supraspinatus control in regards to the humeral head during abduction?
Controls superior roll
What does supraspinatis stabilize during abduction?
The humeral head against the glenoid fossa
What does the supraspinatus restrict during abduction?
Excessive superior humeral translation
What does the supraspinatus do to the superior capsule during abduction?
Pulls it taut to protect against impingement
What does the infraspinatus and teres minor do during abduction?
Externally rotate humerus
What muscles are elevators of the scapulothoracic joint?
Upper trapezius, levator scapulae, rhomboids
What muscles are depressors of the scapulothoracic joint?
Lower trapezius, latissimus dorsi, pectoralis minor, subclavius
What muscle is a protractor of the scapulothoracic joint?
Serratus anterior
What muscles are retractors of the scapulothoracic joint?
Middle trapezius, rhomboids, and lower trapezius
What muscles are upward rotators of the scapulothoracic joint?
Serratus Anterior, Upper trapezius, Lower trapezius
What muscles are downward rotators of the scapulothoracic joint?
Rhomboids, Pectoralis Major
What are the three groups of muscles that work together to elevate the arm?
Muscles that elevate (flex or abduct), scapular muscles, rotator cuff muscles
What does the scapular muscles complete with elevation of the arm?
Control upward rotation of the scapula
What do rotator cuff muscles do when the arm is being elevated?
Muscles control dynamic stability and arthrokinematics of the glenohumeral joint
What muscles extend or adduct the shoulder at the glenohumeral joint?
Posterior Deltoid, latissimus dorsi, teres major, long head of the triceps bracii, sternocostal head of pectoralis major
What are the prime movers of extension or adduction at the GH joint?
Latissimus Dorsi, Teres Major, Sternocostal head of the pectoralis major
What muscles internally rotate the glenohumeral joint?
Subscapularis, Latissimus Dorsi, Teres Major, Pectoralis Major, Anterior Deltoid
What are the prime movers of internal rotation at the glenohumeral joint?
Teres Major, Latisismus Dorsi
What muscles externally rotate at the glenohumeral joint?
Infraspinatus, Teres Minor, Posterior Deltoid
What are the prime movers of external rotation at the glenohumeral joint?
Infraspinatus, Teres Minor